Railway traffic controlling apparatus



NOV. 10, 1942. s,

RAILWAY TRAFFIC CONTROLLING APPARATUS INVENTOR Filed June 28, 1941 N ks: NMNm GEN mum Q5 Q3 R ZMiZZJ HIS ATTORNEY Patented Nov. 10, 1942 RAILWAY TRAFFIC CONTRGLLKNG APPARATUS Robert Miils, Kcw Gardens, N. Y., assignor to The Union Switch and Signal Company, Swissvale, Pa, a corporation of Pennsylvania Application June 28, 1941, Serial No. 400,277

8 Claims.

My invention relates to railway trafiic controlling apparatus, and more particularly to such apparatus for use in governing the movements of trafiic over stretches of track over which traffic moves in either direction.

In governing trafiic movements on a stretch of track over which trafiic moves in either direction, it is customary to provide a traffic locking circuit which prevents the changing of the direction of traffic on the stretch of track while the stretch is occupied or while a signal is displayed for a train to proceed into the stretch. Such traffic locking circuit is usually arranged whereby once the direction of traffic is established the manipulation of levers or control units at the opposite end of the stretch from which trafilc is to move does not disturb the circuit with possible attendant result of placing at stop a signal that may have been set at a proceed position. In such lockout control it is desirable to assure that grounds or similar faults on the traflic locking circuit may not defeat the purpose of the lookout control.

Accordingly, a feature of my invention is the provision of novel and improved railway trafiic controlling apparatus for a traflic locking circuit.

Another feature of my invention is the provision in a traffic locking circuit of novel lockout means which is substantially free from failure due to grounds and like faults on the trafiic looking circuit,

Other advantages and objects of my invention will appear as the specification progresses.

The above features, advantages and objects of my invention I attain by providing two lockout relays for a trafiic locking circuit, one at each end of the circuit, and by providing each such lockout relay with two independent operating windings one of which is interposed in the positive side of the circuit and the other of which winding is interposed in the negative side of the circuit. The two windings of each relay are disposed so as not to oppose each other in the energization of the relay and each winding is independently effective to pick up the relay when energized by the current normally supplied to the traffic locking circuit by the current source. Hence, grounds on either side of the circuit that might art to shunt the winding interposed in the grounded side of the circuit does not prevent the relay from being picked up by energization of the other winding and thus does not act to defeat the lockout function of the relay.

I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

For a better understanding of my invention, reference is made to the accompanying drawing which is a diagrammatic view showing one form of apparatus embodying my invention.

Referring to the drawing, the lineargraph at the top of the drawing illustrates a stretch of single track railway over which traflic moves in either direction between two locations D and E. As here shown, location D includes a track switch i leading to a second track DS, and location E includes a track switch 7 leading to a second track ES. It is to be understood that my invention is not limited to any particular track layout for locations D and E and such locations may not include anyvtrack switches, or they may include additional switches and signals other than those shown in the drawing. The point is, that each location D and E includes one or more tracks leading to the stretch of track between the 10- cations and over which stretch traffic moves in either direction.

Each location D and E is provided with a set of signals for governing traific and in the instant case a signal 2L governs westbound trains and signals ER and 2R0 govern eastbound trains over switch I of location D, while a signal 8R governs eastbound trains and signals 8L and SLC govern westbound trains over switch I at location E. According to standard practice each signal 2R, 2L, 8R and 8L is provided with two signal mechanisms mounted on a single mast, the top mechanism being identified by the reference character A plus a prefix corresponding to the associated signal. The particular arrangement of the signals at each location D and E is however immaterial and may be varied from that shown in the drawing to suit the particular track layout and the form of signals to be used. The significant point concerning these signals as far as the present application is concerned is the fact that signals ZRA and 2R0 govern eastbound movements into the stretch between locations D and E according to the position of switch I, and signals 811A and BLC govern westbound movements into the stretch according to the position of switch 1. In other words, signals ZRA and 2R0 at the west end of the stretch and signals 8LA and 8L0 at the east end of the stretch are opposing signals for this stretch of single track railway. Any standard type of signal may be used and they are shown in the drawing conventionally for the sake of simplicity. It is to be observed that intermediate signals between locations D and E may be provided if desired.

In accordance with the usual practice, this stretch of single track railway is arranged in track circuited sections, detector track sections IT and lT being associated with switches l and l, respectively, and the intermediate portion of the stretch including two sections AT and BT although additional track sections may be formed for this intermediate portion if required. The track relay for the track circuit of each such track section is identified by the reference character R plus a prefix corresponding to the section, and the association of a track relay with the section is indicated by a dash line.

Track switches l and I may be hand operated or power operated and ordinarily they would be power operated but the apparatus and circuits for operating the switches is not shown in the drawing for the sake of simplicity since such apparatus forms no part of my present invention and is not required for an understanding thereof.

Before proceeding further with the description, it should be pointed out that contact fingers of the several track relays and circuit controlling contacts operated by the track switches, as well as contact fingers of other relays to be later described, are in most instances shown remote from the winding of the relay or from the switch. In each such case the contact finger or contact is identified by the reference character corresponding to that of the device by which it is operated and is shown in the position corresponding to the normal position of the operating device.

In order to protect trafic moves in opposite directions through this stretch of track between locations D and E, the signals at location D are associated with the signals at location E by a traffic locking circuit which includes a directional relay and a current source at each location, together with a pair of line wires extending between the two locations. That is, a directional relay IWF and battery DB at location D and a directional relay IEF and battery EB at location E are included in a traffic locking circuit which is completed between locations D and E by line wires LWI and LWZ, and in which line wires there are interposed front contacts of each track relay of the intermediate track sections so that the traffic locking circuit is responsive to traffic conditions of the stretch. As here shown, a so-called double break arrangement is used and front contacts Ill and H of a track relay BTR of section BT are interposed in line wires LWI and LWZ, respectively, and front contacts 112 and [3 of track relay ATR of section AT are interposed in line wires LWI and LWE, respectively. It follows that the traffic locking circuit completed over line wires LWI and LWZ is held open when any one of the intermediate track sections BT and AT is occupied to release the respective track relay. This trafiic locking circuit is also governed by a circuit network at each of the two locations and which networks will be taken up and described when the operation of the apparatus is explained. At this point it is sufficient to note that when an eastbound movement from location D is to be made, the traffic locking circuit is conditioned by the networks to energize directional relay IWF at location D by current supplied by battery EB at location E, and when a westbound movement is to be made from location E, the

traffic locking circuit is conditioned to energize directional relay iEF at location E by current supplied by battery DB at location D. As will shortly appear, each directional relay IWF and IEF controls the signals governing traliic moves into the stretch at the location at which the directional relay is located.

According to my invention, I provide two lockout relays for the traffic locking circuit, a lockout relay IEFL being interposed in the circuit at location D and a lockout relay IWFL being interposed in the circuit at location E. Each lockout relay [EFL and IWFL is provided with two windings, one of which windings is included in the positive side of the traffic locking circuit, and the other of which windings is included in the negative side of the circuit, and each relay is characterized by the fact that each of its windings is eifective when energized by the normal flow of current in the traffic locking circuit to pick up the respective relay. Looking at relay IEFL, this relay is included in the traffic locking circuit when the circuit is conditioned for westbound trafiic and current is supplied to the circuit by battery DB, a top winding I l of relay iEFL being interposed in the positive side of the circuit adjacent the positive terminal of battery DB and a lower winding 15 of relay IEFL being interposed in the negative side of the circuit adjacent the negative terminal of battery DB. Thus normally, current supplied by battery DB fiows in both windings l4 and 15 of relay IEFL and not only is each winding l4 and [5 effective to pick up the relay when thus energized, but the two windings l4 and I5 are disposed to add their effects and the relay is picked up when such current flows in both windings simultaneously. Similarly, relay IWFL is interposed in the traific locking circuit when the circuit is conditioned for easbound trafiic and current is supplied to the circuit from battery EB, a top winding I6 of relay IWFL being interposed in the positive side of the circuit ad- ,iacent the positive terminal of battery EB and a lower winding I! being interposed in the negative side of the circuit adjacent the negative terminal of battery EB. Thus normally, the current supplied to the traffic locking circuit from battery EB fiows in both windings l5 and I? of relay IWFL and not only is each winding effective to pick up the relay alone when thus energized, but the two windings are additive in their effects and the relay is picked up when both windings are simultaneously energized. The function of these lockout relays will be taken up later in the description,

Two traffic following stick relays IWFS and IEFS are preferably placed at locations D and E, respectively, to effect following moves through the stretch. Looking at relay lWFS, a pick-up circuit for the relay is formed from terminal B of any convenient source of current such as a battery not shown, over back contact ill of a relay IWS to be referred to later, front contact IQ of directional relay IWF, winding of relay IWFS and to terminal 0 of the same source of current. With relay IWFS picked up, it is retained energized subsequent to the release of directional relay IWF over a stick circuit including terminal B, back contact 28 of directional relay lWF, front contact 2| and winding of relay IWFS and terminal 0. Relay IEFS at location E is provided with similar pick-up and stick circuits, the pick-up circuit being formed from terminal B of a source of current at location E o'ver back contact 22 of a relay IES to be later referred to, front contact 23 of directional relay lEF and winding of relay IEFS to terminal C; and the stick circuit being formed from terminal B over back contact 24 of relay IEF, front contact 25 and winding of relay IEFS and to terminal C.

At location D, the associated switch and signals are controlled through the medium of an interlocking machine which includes a manually operable lever 2 for controlling the signals 2RA, ZRC and 2L. In accordance with standard practice, signal lever 2 is normally positioned at a mid position N and is operable to either a right-hand position R or to a left-hand position L, circuit controlling contacts being operably connected to the lever for controlling circuits according to the different positions of the lever. Such circuit controlling contacts are shown conventionally with reference characters N, R and L placed thereon to indicate the lever position at which the respective contact is closed. Thus contact 26 is closed at both the normal position N and the left-hand position L of lever 2 and contact 2'! is closed at the right-hand position R only.

Signal lever 2 governs the associated signals ZRA and ZRC when moved to its right-hand position R through the medium of a lever repeater relay 2RLP which relay has contacts interposed in the control network for these signals. The circuit for repeater relay ZRLP comprises terminal B, back contact 30 of lockout relay IEFL, lever contact 21, winding of relay ZRLP and terminal C. Hence relay ZRLP is energized and picked up Whenever signal lever 2 is moved to its right-hand position R providing the lockout relay IEFL at location D is deenergized to close back contact 30 but operation of lever 2 is ineffective to control relay ZRLP as long as the lookout relay IEFL is picked up. Front contact 3| of lever repeater relay ZRLP is interposed in the control network for signal control relays 2RAH and ZRCH, which relays in turn govern the operating circuits for signals ZRA and 2R0, respectively. This control network can be traced from terminal B over front contact 32 of track relay l TR, either front contact 33 of directional relay IWF or front contact 34 of trafiic following stick relay IWFS, front contact 3| of lever repeater relay ZRLP. contact IC operated by switch I and moved to its full line position when switch I is set at its normal position, winding of relay 2RAH and to terminal C. In the event switch I is set at its reverse position causing contact I C to occupy its position indicated by the dotted lines in the drawing then this circuit network is C0111? pleted over winding of relay ZRCI-I and to terminal C. Thus when lever 2 is moved to its R position to pick up repeater relay ZRLP and the circuit network is properly conditioned, signal control relay 2RAH is selected if the switch I is at its normal position and the signal control relay ZRCI-I is selected when switch I is set at its reverse position. It should be pointed out of course that according to standard practice the signal control network for relays 2RAH and ZRCH would include the usual approach control, route locking control and other traffic governing devices but which control is omitted from the drawing for the sake of simplicity since such trafiic controlled devices form no part of my invention.

Signal control relay 2RAH governs the operationof signal 2RA. The manner whereby relay 2RAH governs the operation of signal ZRA would be in accordance with the type of signal used and as here shown relay 2RAH when picked up to close front contact 35, completes an operating circuit by which signal 2RA is operated as required to display a Proceed signal indication, and when relay 2RAH is released to close back contact 36, an operating circuit is completed by which signal ZRA is operated as required to display a stop signal indication. In like manner relay ZRCH when picked up to close front contact 37 completes an operating circuit by which signal ZRC is operated as required to display a proceed signal indication, and when released to close back contact 38 an operating circuit is closed to operate signal 2RC as required to display a stop signal indication.

Signal lever 2 in addition to governing the repeater relay 2RLP also governs a normally energized route locking relay IWS which is associated with the traflic locking circuit. In the instant case, the circuit for relay IWS comprises terminal B, back contact 28 of relay 2RLP, front contact 29 of track relay ITR, lever contact 26, winding of relay IWS and terminal C. It is to be pointedo'ut that when the track layout at location D includes switches of additional routes, the control of route locking relay IWS would be governed by such additional switches and routes as required.

At location E, the associated switch and signals are manually controlled through a remote control system. The type of .remote control is immaterial and may be any one of several wellknown systems, and it is sufiicient for this appli cation to point out that each of the signals and switches would be provided with a respective remote control relay which when picked up completes circuits by which the respective device is governed. Of such remote control relays, only the relay ELSR for governing signals BLA and 8LC is shown since such is the only one involved in my invention. As here illustrated, a preselected control transmitted from some remote station by the remote control system causes positive energy to appear at terminal 39 of a remote control unit and current flows from terminal 39 over back contact 40 of lockout relay IWFL, winding of remote control relay fiLSR and to negative terminal C of the same source of current. and relay '8LSR is manually controlled by being picked up in response to such remote control providing the lookout relay IWFL is released. In the eventrlockout relay I WFL is picked up to open back contact 40 the remote control system is ineffective to govern relay BLSR. Remote control relay BLSR governs the circuit network for signal control relays 8LAH and BLCH for signals 8LA and SLC, respectively. This circuit network for relays BLAH and BLCH includes terminal B. from contact M of track relay 'ITR, either front contact 42 of directional relay iEF or front contact 43 of traffic following stick relay iEFS, front contact 44 of remote control relay ELSR, contact lC operated by switch I and moved to its full line position when switch 1 is set at its normal position, winding of relay BLAH and terminal C; and when switch 7 is moved to its reverse position to-cause contact FC to occupy the position indicated by the dotted lines in the drawing this circuit network is completed over winding of relay 3LCH to terminal C. Thus when remote control relay 8LSR is picked up and the circuit network is in the proper condition,1relay SLAI-I is selected when switch i is set at it's normal' position and relay BLCI-I is selected when switch 7 is set at its reverse position. Relay SLAl-I governs the operating circuits for signal 8LA, the arrangement being such that when relay fiLA-H is picked up .to close front contact 45 an operating circuit is formed by which lgnal BLA is operated as required to display a proceed signal indication, and when relay BLAH is released to close back contact 46, an operating circuit is formed by which'signal 8LA is operated as required to display a stop signal indication. Relay fiLCl-I governs the operating circuits for signal SLC in a similar manner, the signal being operated as required to display. a proceed signal indication when relay BLCH is picked up to close front contact 41 and to display a stop signal indication when relay 8LCH is released closing back contact 48.

The remote control relay 8LSR also governs a normally energized route locking relay 'IES associated with the traffic locking circuit at location E. Route locking relay IE8 is normally energized over a circuit comprising terminal B, back contact 49 of relay SLSR, front contact 56 of track relay 'lTR, winding of relay IE8 and terminal C. l-Ience relay IE8 is released whenever remote control relay BLSR is picked up in response to a remote control sent to location E. It is to be noted that the circuit network for the signal control relays 8LAH and BLCH would inelude-the usual approach locking and other associated traffic governed devices but which are not shown as they form no part of my present invention. Likewise, the circuit formed for the route locking relay 'IES would be governed by any additional switches, routes and other devices included in the track layout of location E when such. additional routes are involved in the stretch of track between the two locations D and E.

.. In describing the operation of the apparatus,

I shall at first assume that the apparatus is in its normal position, that is, in the position illustrated in the drawing. Under such normal condition, the track relays are all picked up and the route locking relays lWS and IE8 at. locations D and E, respectively, are energized but all the remaining relays are deenergized and released causing all the signals to be set to indicate stop. The tramc locking circuit is also normally deenergized because the two batteries DB and EB which are of substantially the same voltage, are connected to the circuit in series opposition and asymmetric units are interposed in the circuit. To be explicit, the traffic locking circuit can be traced from the positive terminal of battery DB over top winding M of lock-out relay IEFL, an asymmetric unit inits forward direction, resistor 52, back contact 53 of directional relay IWE, back contact 5 f traffic following stick relay -!WF-S, front contact'55 of route locking relay lWS, front contact ID of track relay BTR, line-wire LWI, front contact l2 of track relay ATR, front contact 56 of route locking relay 'IES, back contact 5'1 of traffic following stick relay IEFS, back contact 58 of directional relay IEF, resistor 59, asymmetric unit 60. in its blocking direction, top winding l6 of lockout relay IWFL, positive terminal of. battery EB to the negative terminal of that battery, lower winding ll of relay IWFL, back contact 6| of relay IEF, back contact 62 of relay IEFS, front contact 63 of relay 'IES, front contact i3 of relay A'I'R, line wire LWZ, front contact. ll of relayBTR; front contact 64 of relay IWS, back contact 65 of relay IWFS, back contact 66 of relay IWF, lower winding l5 of relay IEFL and to the negative terminal of battery DB. As stated hereinbefore, batteries DB and EB are of substantially the same voltage and oppose each other when the trafiic locking circuit is in its normal condition. Also, it is to be noted that in the event there is an unbalanced voltage condition between the two batteries DB and EB, the asymmetric units 5| and 60 block the flow of current from one battery through the other battery.

I shall next assume that an eastbound train is to move east from location D and to that end eastbound direction of traffic is established for the traffic locking circuit and signal 2RA or ZRC is cleared. Lever 2 is moved to its R. position to effect this change. Movement of lever 2 to its R position opens the circuit for route locking relay IWS and that relay releases to disconnect battery DB from the trafiic locking circuit and to connect the directional relay IWF thereto. That is, the trafiic locking circuit is now conditioned for energization of directional relay IWF by current from battery EB for establishing eastbound direction of traffi-c, and the circuit is formed from the positive terminal of battery EB over upper winding 16 of relay lWFL, asymmetric unit 60 in its forward direction, resistor 59, back contacts 58 and 5! of relays IEF and 'IEFS, respectively, front contacts and H of relays YES and ATR, respectively, line wire LWl, front contact [0 of relay BTR, back contact 61 of relay IWS, winding of directional relay IWF, back contact 68 of relay IWS, front contact H of relay BTR, line wire LWZ, front contacts 13 and 63 of relays ATR and ms, respectively, back contacts 62 and 6! of relays IEFS and IEF, respectively, lower winding I! of relay IWFL and to the negative terminal of battery EB. Directional relay IWF at location D and lockout relay IWFL at location E are now energized in series and picked up. Since relay ZRLP is energized when signal lever 2 is moved to its R position, the picking up of directional relay IWF to close front contact 33 completes the signal control network for relay ZRAH or ZRCH and one of these relays is picked up depending upon the position of switch I and one of the respective signals ZRA or 2R0 is operated to a proceed position to permit the eastbound train to move from location D into the stretch of single track toward location E.

It is to be noted that in the event a control is inadvertently sent to location E for energizing remote control relay 8LSR after signal lever 2 at location D has been moved to its R position and the trafllc locking circuit conditioned for eastbound direction of traffic, such remote control is ineffective to energize relay BLSR because back contact 40 of lockout relay IWFL is now open. That is, the traflic locking circuit locks out a control from being put into effect to clear a westbound signal at location E after an eastbound signal has been cleared at location D. Furthermore, it is to be noted that in the event the'negative terminal of battery EB is grounded and a second ground occurs on the negative side of the traffic locking circuit such as, for example, a second ground occurs on line wire LW2, the current supplied to the traffic line circuit would flow in the directional relay lWF energizing that relay, but might be shunted away from the lower winding ll of lockout relay IWFL. Such shunting of the current away from winding ll of relay IWFL does not result in a failure of relay IWFL from" picking up to lock out the control of relay BLSR' because the energization of the top winding I6 of relay IWFL is efie-ctive to pick up the relay. In a like manner two grounds on the positive side of the trafiic locking circuit might shunt current away from Winding l6 of relay IWFL but in this case the relay would pick up because of the energization of the lower winding ll, to lock out the control relay 8LSR. In the case both sides of the trailic locking circuit are grounded, then battery EB is shunted and the traffic locking circuit is deenergized and directional relay IWFL would not be picked up to establish eastbound direction of tramc.

I shall next assume that signal ERA or 2R0, as the case may be, has been cleared in the manner described hereinbefore and that an eastbound train advances from location D. The shunting of track relay [TR by the train in section IT deenergizes signal control relay ZRAH or 2RCH as the case may be, and causes the respective signal to be restored to its stop position. When the eastbound train advances into section BT to shunt track relay BTR, the trafiic locking circuit is opened and directional relay IWF is released. and remains released until the train clears section AT at location E and the trafiiclocking circuit isreclosed. Traffic following stick relay IWFS is energized over its pick-up circuit when directional relay IWF isfirst picked up and route locking relay IWS is released and relay IWFS remains picked up over its stick circuit subsequent to the release of relay I WF with the eastbound train in section BT or AT. Relay IWFS when picked up to close front contact 3 3- prepares the control network for relays ZRAI-I' and @RCH and one of these relays is energized according to the position of switch I to clear the respective signal ERA or 2R0 to permit a second or following eastbound train to enter the stretch of track. As here shown, signal ZRA or ZRC would be cleared automatically for the second eastbound train, but it is apparent that the wellknown stick arrangement requiring operation of the signal lever 2- first back to-its normal position and then to its R position to clear a signal for a second train may be used if desired.

I shall next assume that the apparatus is at its normal position and it is desired to send a Westbound train from location E. A remote control is transmitted to energize remote control relay BLSR and that relay is picked up to deenergize the route locking relay (ES and to prepare the control network of the signal control relays BLAH and 8LCI-I. When routelockin relay IE is released, battery EB is disconnected from the traffic locking circuit and the directional relay IEF is connected thereto, and the traffic locking circuit is conditioned for energization of relay IEF by battery DB, current flowing from the positive terminal of battery DB over top'winding M of relay PEFL, asymmetric unit 5| in its forward direction, resistor 52, back contact 53 of relay IWF; back contact 54 of relay IWFS, front contact 55 of relay IWS, front contact I c of relay BTR', line wire LWI, front contact l2 of relay ATR, back contact 69 of relay TES, Winding of directional relay IEF, back contact 76' of relay'lES, front contact l3 of relay ATR, line wire LWZ, front contact I I of relay BTR, front contact-64 of relay IWS, back contact 65 of relay IWFS, back contact 66 of relay IWF, lower winding l5 of relay IEFL and to the negative terminal of battery DBL Directional relay IEF at location E and lockout relay IEFL at location D are energized in series and picked up The picking up of relay lEF to close front contact 42 completes the circuit network for relay 8LAH or BLCI-I and one of these relays is selected according to the position of switch I and the corresponding signal SLA or 8L0 is operated to a proceed position to permit a westbound train to move from location E. The picking up of relay IEFL opening back contact 33- locks out control of' relay ZRLP;

In the event signal lever 2 is inadvertently moved to its R position in an attempt to establish an eastbound direction of tralhc, the relay ERLP does not respond because-of the opening of back contact 30 of lockout relay l-EFL. Thus such inadvertentmovement of signal lever 2 does not disturb the traffic locking circuit and any westbound signal" at location E that has been operated to a proceed position is not set at a stop position. It is to be observed that while such inadvertent movement of lever 2 would release relay I'WS and open the trafiic locking circuit to release relay IEF at location E, the control for relay SLAH or 8LCH is not disturbed because relay IEFS is picked up closing at its front contact t3 the circuit for relays BLAH and 8LCH. Itis also to be pointed out that in case the negative terminal of battery DB is grounded and-there occurs a second ground on the negative side of the traiiic locking circuit, lockout relay IEFL is picked up due to'energization of the top winding M although this ground condition may shunt the current away from the lower winding E5 of that relay. Likewise a grounded condition of the'positiveside of the trafl'io locking circuit that might shunt current away from the top winding is of relay IEFL does not cause the relay to fail to pick up since energization of the lower winding l 5 is eitective to pick up the relay.

Trafiic following stick relay IEFS is picked up when directional relay IEF is picked up and the route-locking relay IE8 is released, and then is retained energized over its stick circuit subsequent to the westbound train entering section AT to open the trafiic locking circuit and deenergize the directional relay IEF. With relay IEFS picked up to close front contact t3, the circuit network is completed by which signal control relay BLAH or 8LCH is picked up and the corresponding signal 8LA or 8L0 is cleared to'permit a second westbound train to enter the stretch of single track.

Although" I have shown the apparatus at loca-' tion-D manually controlled by aninterlocking machine and the apparatus at location E manually controlled by a remote control system, it is apparent that the type of signal controlhas no bearing on my present invention and an interlocking machine may be used at each location or each location may be controlled by a remote control system if desired;

Apparatus here provided possesses the advantages that absolute check between opposing signals is provided, a change in the direction of trafiic by inadvertent operation of a; lever or control unit for the direction of tr'a'fli'c opposite to that established is avoided, separate trafiic levers or control units are not required since the trafiic locking circuit is controlled indirectly by the signal lever or signal control unit through route locking relays, provision is made for following permissive moves, and a lookout condition is not lost be'cause of a grounded condition of the traffic locking circuit;

Although I have herein shown and described onlyon'e form of railway't'raffic controlling appa."

ratus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In railway traffic controlling apparatus for use with a stretch of track provided with a signal at each end to govern traffic through the stretch, the combination comprising, a traffic locking circuit including a directional relay and a current source at each end of the stretch, means including a manually controlled device at each end of the stretch to connect the directional relay at one end of the stretch and the current source at the other end to said traffic locking circuit or to connect the directional relay at said other end and the current source at said one end to such circuit, two lockout relays one at each end of the stretch, two windings for each lockout relay one winding of each relay interposed in the traific locking circuit adjacent one terminal of the current source at the same end of the stretch as the relay and the other winding of each such lockout relay interposed in the traffic locking circuit adjacent the other terminal of the current source at the same end of the stretch as the relay, and control means for each signal including a front contact of the directional relay and a back contact of the lockout relay at the same end of the stretch as the respective signal.

2. In railway traffic controlling apparatus for use with a stretch of track provided with a signal at each end to govern traffic through the stretch,

the combination comprising, a trafiic locking circuit including a directional relay and a current source at each end of the stretch, circuit means controlled by each directional relay when energized to clear the signal at the same end of the stretch and establish the direction of traffic over the stretch, manually controlled means at each end of the stretch eflective to connect either the direction relay or the current source at the same end of the stretch to the trafiic locking circuit for selectively energizing the directional relays, two lockout relays one at each end of the stretch, two windings for each lockout relay one winding of each lockout relay interposed in each side of the lockout circuit adjacent the current source at the same end of the stretch as the relay to energize each lockout relay in serieswith the directional relay at the opposite end, and means controlled by each lockout relay when energized to render ineffective the manually controlled means at the same end of the stretch.

3. In railway trafiic controlling apparatus for use with a stretch of track provided with a signal at each end to govern traffic through the stretch, the combination comprising, a traihc locking circuit including a directional relay and a current source at each end of the stretch, circuit means controlled by each directional relay when energized to clear the signal at the same end of the stretch and establish the direction of traffic over the stretch, manually controlled means at each end of the stretch effective to connect either the directional relay or the current source at the same end of the stretch to the traffic locking circuit for selectively energizing the directional relays, two lockout relays one at each end of the stretch, two windings for each lockout relay one winding of each lockout relay interposed in each side of the lockout circuit adjacent the current source at the same end of the 7 stretch as the relay to energize each lockout relay in series with the directional relay at the opposite end, each winding of each lockout relay effective when energized by the current normally supplied to the traflic locking circuit by the associated current source to pick up the relay and the two windings of each lockout relay disposed to add their effects, and means controlled by each lockout relay when picked up to render ineffective the manually controlled means at the same end of the stretch.

4. In railway traffic controlling apparatus for use with a stretch of track arranged in track circuited sections and provided with a signal at each end to govern traffic into the stretch, the combination comprising, a trafiic locking circuit including a directional relay and a current source at each end of the stretch and controlled by the track circuit of each said section, means at each end of the stretch including a manually controlled unit to connect either the directional relay or the current source at the same end of the stretch to said traffic locking circuit to energize a directional relay by current supplied by the C source at the other end of the stretch, two lockout relays one at each end of the stretch and each such lockout relay including two windings interposed in the traffic locking circuit one winding adjacent one terminal of the current source at the same end of the stretch and the other winding adjacent the other terminal of that current source, each winding of each lockout relay effective when energized by the current normally supplied to the traffic locking circuit to pick up the respective relay, and control means for each signal and each such control means including a front contact of the directional relay and a back contact of the lockout relay at the same end of the stretch.

5. In railway trafic controlling apparatus for use with a stretch of track arranged in track circuited sections and provided with a signal at each end to govern traffic into the stretch, the combination comprising, a traffic locking circuit including a directional relay and a current source at each end of the stretch and controlled by the track circuits of said sections, a manually controlled unit at each end of the stretch, circuit means at each end of the stretch including a contact of the respective manually controlled unit to connect the respective directional relay to the traffic locking circuit for energization of that relay by the current source at the opposite end of the stretch to establish the direction of traffic over the stretch, a circuit network at each end of the stretch including a contact of the respective manually controlled means and a contact of the respective directional relay when energized to clear the respective signal, two lockout relays one at each end of the stretch, two windings for each lockout relay one winding interposed in each side of the traffic locking circuit adjacent the current source at the same end of the stretch to energize each lockout relay in series with the directional relay at the opposite end of the stretch,

each winding of each lockout relay effective when thus energized to pick up the relay and the two windings of each lockout relay arranged to add their effects, and a back contact of each lockout relay interposed in said circuit network at the same end of the stretch.

6. In railway traflic controlling apparatus for use with a stretch of track arranged in track circuited sections and provided with a signal at each end to govern traffic over the stretch, the

combination comprising, a two-wire trafiic looking circuit controlled by each of the track circuits and provided with a directional relay and a current source at each end of the stretch, control means at each end of the stretch and each control means operative to connect either the directional relay or current source at the same end of the stretch across the two wires of the traffic locking circuit for selectively energizing the directional relays to establish the direction of traffic over the stretch, two lockout relays one at each end of the stretch and each lockout relay including two windings one interposed in the connection of each wire of said trafiic locking circuit to the current source at the same end of the stretch, each said lockout relay effectively energized and picked up when either of its two windings is energized by the current normally supplied by the associated current source to the trafic locking circuit, a control circuit network for each of said signals and each such network including a front contact of the directional relay at the same end of the stretch, and means controlled by each lockout relay when picked up to render the control means at the same end of the stretch inefiective to disturb the direction of traffic established by the trailic locking circuit.

7. In railway trafiic controlling apparatus for use with a stretch of track arranged in track circuited sections and provided with a signal at each end to govern trailic over the stretch, the combination comprising, a two-wire traffic locking circuit controlled by each of the track circuits and provided with a directional relay and a current source at each end of the stretch, control means at each end of the stretch and each control means operative to connect either the directional relay or current source at the same end of the stretch across the two wires of the traffic locking circuit for selectively energizing the directional relays to establish the direction of traffic over the stretch, two lockout relays one at each end of the stretch and each lockout relay including two windings one interposed in the connection of each wire of said traiiic locking circuit to the current source at the same end of the stretch, each winding of each lockout relay efiective to pick up the relay when energized by the current normally supplied to the traffic locking circuit by the respective current source and the two windings of each such relay additive in their effects, a control circuit network for each of said signals and each such network including a front contact of the directional relay at the same end of the stretch, and a back contact of each lockout relay interposed in said control means at the same end of the stretch to cause that control means to be inoperative to disturb the established condition of said trafiic locking circuit when the lookout relay is picked up.

8. In railway trafiic controlling apparatus for use with a stretch of track arranged in track circuited sections and provided with a signal at each end to govern trafiic over the stretch, the combination comprising, a trafilc locking circuit including a directional relay and a current source at each end of the stretch together with two line wires extending between the two ends and having interposed therein a contact controlled by each such track circuit, a route locking relay at each end of the stretch to connect either the directional relay or current source at the same end to said line wires to selectively energize the directional relays and establish the direction of traffic over the stretch providing the stretch is unoccupied, a two winding lockout relay at each end of the stretch; each lockout relay having one winding included in the traffic locking circuit adjacent one terminal of the current source at the same end of the stretch and its second winding included in the traffic locking circuit adjacent the other terminal of that current source, said two windings of each lockout relay additive in their effects and each winding effective to pick up the relay when supplied with the current normally in the trafiic locking circuit whereby the lockout relay at one end of the stretch is picked up when the trafiic locking circuit is conditioned by the route locking relays to pick up the directional relay at the other end of the stretch notwithstanding grounds exist on one side of the trafiic locking circuit. means controlled by each directional relay when energized to clear the Sig-- nal at the same end of the stretch, and a manually controlled circuit for each route locking relay and each such circuit including a back contact of the lookout relay at the same end of the stretch.

ROBERT MILLS. 

